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Chapter 5 PC Operation - Tutorial
5.1 Introduction
The following brief tutorial guides the user through a typical series of moves and
parameter adjustments performed using the PC based APT software. It assumes that
the unit is electrically connected as shown in Section 3.3.1. that the APT Software is
already installed - see Section 3.1. and that the stage being driven is the Thorlabs
DDSM100 Direct Drive Translation stage.
Warning
The APTServer includes built in safety features which prevent the user from
performing a move before the actuators being driven have been ‘homed’. If a
custom software application, which operates outside of the APTServer, is
being used to position the actuator, then these safety features will not be
implemented. In this case, it is the responsibility of the user to home the
motors before performing any further moves. Failure to home the motors will
cause an error in positional information which could result in damage to the
unit and possible injury to personnel operating the equipment.
Caution
The maximum velocity at which the encoder can operate is approximately
600 mm/sec. Above this speed, encoder pulses may be lost and, as a
result, the position readout becomes incorrect. This renders normal
operation impossible because phase commutation of the motor is also
based on the encoder reading.
When the stage is controlled by the KBD101 driver, the maximum velocity
is limited to safe values. However, if the output is disabled (with the driver
connected and monitoring the position) and the stage is moved manually
at high speeds, it is possible to exceed this limit. If the KBD101 driver is
subsequently used again to move the stage, the incorrect encoder
reading will cause incorrect operation, often resulting in sudden
uncontrolled moves. It is therefore important not to move the stage
excessively quickly when it is moved manually.
The TBD driver has fault monitoring to detect the loss of encoder pulses.
If this fault occurs, an error message will be generated and the driver
must be powered down and re-started so that correct phasing and
commutation can be established.
